三峡库区巫山县塔坪H1滑坡变形机制  

Deformation mechanism of the Taping H1 landslide in Wushan County in the Three Gorges Reservoir area

作　　者：卫童瑶 殷跃平 高杨[3] 李滨[1,3] 贺凯[3] 唐俊刚 张天贵 WEI Tongyao;YIN Yueping;GAO Yang;LI Bin;HE Kai;TANG Jungang;ZHANG Tiangui(Department of Geological Engineering,Chang’an University, Xi’an, Shaanxi 710054,China;China Institute of Geo-Enviroment Monitoring (Consultative Centre of Geo-Hazard Mitigation,MNR), Beijing 100081, China;Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081,China;No.107 Team of Chongqing Geology Exploring Bureau, Chongqing 401120, China)

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054 [2]中国地质环境监测院(自然资源部地质灾害技术指导中心),北京100081 [3]中国地质科学院地质力学研究所,北京100081 [4]重庆市地质矿产勘查开发局107地质队,重庆401120

出　　处：《水文地质工程地质》2020年第4期73-81,共9页Hydrogeology & Engineering Geology

基　　金：国家重点研发计划项目(2018YFC1504800);国家自然科学青年基金(41907257)。

摘　　要：自2008年三峡库区175 m试验性蓄水以来,受库水波动及强降雨影响,沿江库岸发生多起顺向古滑坡变形灾害。以三峡库区巫山县塔坪H1滑坡为例,结合近十年滑坡调查勘察与变形监测资料,分析了该滑坡蓄水后的变形特征。通过研究分析认为:(1)塔坪H1滑坡为顺层古岩质滑坡,岩体呈碎裂状,岩性主要为三叠系香溪组软硬相间的砂岩、泥页岩,岩层间夹多套软弱夹层,形成了多级滑带控制的滑坡变形。(2)滑坡变形分为3个区域,位移量变形最大的滑坡前缘消落带区域,最大水平位移已达80 cm,其次是处于缓慢变形状态的曲尺场镇前部区域和后部相对稳定的曲尺场镇区域。(3)数值模拟结果显示,库水位周期性波动影响着滑坡前缘涉水区域稳定性变化,短时强降雨沿岩体结构面入渗会加速滑坡中前部区域稳定性快速下降。在水位波动和短时强降雨的共同影响下,塔坪H1滑坡在每年汛期呈现缓慢变形。目前塔坪H1滑坡中前部处于持续变形阶段,亟需开展滑坡防治工程,提高滑坡稳定性,确保场镇安全。Affected by the water level fluctuations and heavy rainfall,several bedding rock landslides have reactivated since the 175 m trail impoundment in the Three Gorges Reservoir area.The Taping H1 landslide near Quchi in Wushan County is taken as an example,and combining the landslide investigation and monitoring,the deformation characteristics and reactivation mechanism of the landslide are analyzed.The research results show that(1)the Taping H1 landslide is an ancient bedding rock landslide,the rock mass is fragmented and is mainly composed of soft and hard sandstone,mudstone and shale of the Triassic Xiangxi Group,which is sandwiched by multiple layers of weak inter layers,forming a multi-stage slip zone to control landslide deformation.(2)According to the monitoring of surface and underground displacements,the deformation of the landslide is divided into three regions.The maximum horizontal displacement of the landslide leading zone of the landslide with the largest displacement has reached 80 cm.The middle area of the landslide is slowly deformed,and the area of the rear Quchi Township is relatively stable.(3)The numerical simulation results show that the water level fluctuations influences the deformation and stability of the landslide leading edge which is below the water surface,and the heavy rainfall infiltration along the structural plane accelerates the deformation of the front area of the landslide.The middle and front areas of the Taping H1 landslide is currently in the stage of continuous deformation.Under the combined influence of water level fluctuations and short-term heavy rainfall,the Taping H1 landslide shows a slow deformation during the annual flood season,which is consistent with the monitoring results.Landslide prevention projects are urgently needed to improve the stability of the landslide and ensure the safety of the town.

关 键 词：三峡库区 顺向滑坡 水位波动 变形机理 数值模拟 

分 类 号：P642.22[天文地球—工程地质学]